铑在不同载体材料上的分配比对低含量贵金属催化剂性能的影响  

Effects of the Ratio of Rh on Different Support Materials on Properties of Low-precious Metal Catalysts

作　　者：郭家秀[1] 龚茂初[1] 袁书华[1] 沈美[1] 王娟芸[1] 陈耀强[1] 

机构地区：[1]四川大学化学学院,四川成都610064

出　　处：《贵金属》2006年第1期27-32,共6页Precious Metals

基　　金：国家自然科学重点基金(No.20333030);国家自然科学基金(No.20273043)资助项目

摘　　要：采用浸渍法制备了一系列低Pt、Rh含量的Pt-Rh型汽车尾气净化催化剂。研究了在Pt、Rh含量一定以及其他条件不变的情况下,只改变铑在不同载体上的分配比对催化剂性能的影响,测定了催化剂对C3H8、CO、NO的起燃温度,并对催化剂样品进行了程序升温还原(H2-TPR)、程序升温脱附(O2-TPD)表征。结果表明:新鲜催化剂对C3H8、CO、NO的起燃温度相差不大,但经过1000℃、5h的水热老化后,催化剂性能发生了显著的变化,C3H8、CO、NO的起燃温度出现较大的差异,说明了铑在不同载体上的分配比对催化剂性能有一定影响,特别是对催化剂的抗老化性能影响较大。A series of low Pt-Rh catalysts for automobile exhaust purification was prepared by dipping method. The effect of distribution ratio of Rh on two different supports on catalytic per- formance of the low Pt-Rh three way catalysts was investigated and the light-off temperatures of hydrocarbon and carbon monoxide and nitrogen oxides were measured. The catalysts were characterized by means of the temperature-programmed reduction（TPR） and the temperature- programmed desorption（TPD）. The results of the test showed that the light-off temperatures of hydrocarbon and carbon monoxide and nitrogen oxides have little difference for the fresh catalysts, but for the catalysts treated by the hydrothermal-ageing for 5 hours at 1000℃ the great differences in the light-off temperature are observed. The best ratio of Rh on different supports can improve the property of the catalysts, specially, the anti-aging property.

关 键 词：催化化学 Pt-Rh 催化剂 程序升温还原 程序升温脱附 

分 类 号：O643.36[理学—物理化学]